Slave bluetooth device switching between active bluetooth connections with different master bluetooth devices

ABSTRACT

A slave Bluetooth device establishes first and second connections with first and second master Bluetooth devices, respectively, that each operate in a master mode. The slave Bluetooth device operates in a slave mode when communicating through any of the first and second connections. The slave Bluetooth device communicates connection parameter update request packets containing timeout values to the first and second master Bluetooth devices. The slave Bluetooth device alternates during non-overlapping time slots between at least: 1) monitoring the first connection for traffic transmitted by the first master Bluetooth device while not monitoring the second connection; and 2) monitoring the second connection for traffic transmitted by the second master Bluetooth device while not monitoring the first connection; and controls a rate at which the alternating is performed based on the first timeout value and the second timeout value.

FIELD OF THE INVENTION

The present disclosure relates to Bluetooth communication protocoldevices and related interconnection of peripheral devices and a videodisplay unit using Bluetooth communication connections.

BACKGROUND

Bluetooth Low Energy (BLE) technology provides connectivity betweenmobile devices and a variety of systems, e.g., video displays, remotecontrollers, mobile phones, computers, tablets, headphones, cars, etc.The BLE technology supports a relatively low power consumption for themobile devices. According to the BLE technology, a first Bluetoothdevice (“master Bluetooth device”) operating in a master mode and asecond Bluetooth device (“slave Bluetooth device”) operating in a slavemode establish a connection through which they can transmit and receivedata using radio frequency signaling.

Many applications have arisen where there is a need to connect one BLEdevice to multiple BLE devices, such as to connect an entertainmentsystem to wireless headphones and a mobile phone. Some BLE devices nowinclude two or more separate BLE transceiver circuits to enablemaintenance of simultaneous connections to a corresponding two or moreother BLE devices. The incremental additional cost and design andmanufacturing complexity of including more than one BLE transceivercircuit in a BLE device for these purposes can become prohibitive forsome applications, such as for In-flight entertainment (IFE) systemswhere BLE transceiver circuits can be integrated in seat video displayunits (SVDUs) installed in hundreds of passenger seats onboard anaircraft.

SUMMARY

Bluetooth protocol standards and commercially available devicescontemplate that any Bluetooth device that is operating in a slave mode(referred to as a “slave Bluetooth device”) can have only one connectionto another Bluetooth device that is operating in a master mode (referredto as a “master Bluetooth device”). Thus, if more than one simultaneousconnection is desired, the slave Bluetooth device must include two ormore separate Bluetooth transceiver circuits to enable simultaneousactive connections to a corresponding two or more other master Bluetoothdevices.

Some embodiments of the present disclosure may arise from the presentrealization that a slave Bluetooth device can control a single Bluetoothtransceiver to sequentially establish connections to a plurality ofmaster Bluetooth devices, and then alternate between those connectionsto serve communications from the master Bluetooth devices at a rate thatis sufficient to prevent any of the master Bluetooth devices fromerroneously determining that the slave Bluetooth device is missing andresultantly tearing down its respective connection to the slaveBluetooth device.

One example embodiment of the present disclosure is directed to a slaveBluetooth device that includes a Bluetooth transceiver, at least oneprocessor connected to the Bluetooth transceiver, and at least onememory connected to the at least one processor and storing program codethat is executed by the at least one processor to perform operations.The operations include establishing a first connection through theBluetooth transceiver with a first master Bluetooth device that operatesin a master mode. The slave Bluetooth device operates in a slave modewhen communicating through the first connection. The operations furtherinclude communicating a first connection parameter update request packetcontaining a first timeout value through the Bluetooth transceiver andthe first connection to the first master Bluetooth device, andestablishing a second connection through the Bluetooth transceiver witha second master Bluetooth device that operates in a master mode. Theslave Bluetooth device operates in the slave mode when communicatingthrough the second connection. The operations further includecommunicating a second connection parameter update request packetcontaining a second timeout value through the Bluetooth transceiver andthe second connection to the second master Bluetooth device. The slaveBluetooth device then alternates during non-overlapping time slotsbetween at least: 1) monitoring the first connection for traffictransmitted by the first master Bluetooth device while not monitoringthe second connection; and 2) monitoring the second connection fortraffic transmitted by the second master Bluetooth device while notmonitoring the first connection. A rate at which the alternating isperformed is controlled based on the first timeout value and the secondtimeout value.

Other Bluetooth devices, video display units, systems, and correspondingmethods according to embodiments of the inventive subject matter will beor become apparent to one with skill in the art upon review of thefollowing drawings and detailed description. It is intended that allsuch additional Bluetooth devices, video display units, systems, andcorresponding methods be included within this description, be within thescope of the present inventive subject matter, and be protected by theaccompanying claims. Moreover, it is intended that all embodimentsdisclosed herein can be implemented separately or combined in any wayand/or combination.

BRIEF DESCRIPTION OF THE DRAWINGS

Other features of embodiments will be more readily understood from thefollowing detailed description of specific embodiments thereof when readin conjunction with the accompanying drawings, in which:

FIG. 1 illustrates an aircraft cabin containing an in-flightentertainment (IFE) system having a content server that streamselectronic content through wireless access points (WAPs) to passengerequipment and/or through a wired network to seat video display units(SVDUs) that are controlled by wireless controllers, in accordance withsome embodiments of the present disclosure;

FIG. 2 is a block diagram illustrating some components of the IFE systemof FIG. 1 that are configured to operate in accordance with someembodiments of the present disclosure;

FIGS. 3A-3B are a combined block diagram and data flow diagramillustrating operations and methods for establishing connections fromone SVDU device operating as a slave to a plurality of other devicesoperating as masters, the slave device alternating between theconnections to service communications from the master devices, inaccordance with some embodiments of the present disclosure;

FIGS. 4-5 are flowcharts of operations and methods by the slave deviceto control the master devices to enable the slave device to jump betweenthe connections to service the communications from the master devicesand maintain the connections in a simultaneously active state, inaccordance with some embodiments of the present disclosure;

FIG. 6 illustrates Bluetooth discovery and connection operations with awhitelist and channel-map in accordance with some embodiments of thepresent disclosure;

FIG. 7 is a flowchart and data flow diagram for various operationalstates of Bluetooth transceivers in the Bluetooth devices of the systemof FIGS. 1-6 in accordance with some embodiments of the presentdisclosure;

FIG. 8 is a state diagram for various operational states of Bluetoothtransceivers in the Bluetooth devices of the system of FIGS. 1-7 inaccordance with some embodiments of the present disclosure;

FIG. 9 is a block diagram of a display unit configured to operate inaccordance with some embodiments of the present disclosure; and

FIG. 10 is a block diagram of a Bluetooth device configured to operatein accordance with some embodiments of the present disclosure.

DETAILED DESCRIPTION

In the following detailed description, numerous specific details are setforth in order to provide a thorough understanding of embodiments of thepresent disclosure. However, it will be understood by those skilled inthe art that the present invention may be practiced without thesespecific details. In other instances, well-known methods, procedures,components and circuits have not been described in detail so as not toobscure the present invention. It is intended that all embodimentsdisclosed herein can be implemented separately or combined in any wayand/or combination.

The Bluetooth protocol standards and commercially available devicescontemplate that any Bluetooth device that is operating in a slave mode(referred to as a “slave Bluetooth device”) can have only one connectionto another Bluetooth device that is operating in a master mode (referredto as a “master Bluetooth device”). Thus, if more than one simultaneousconnection is desired, the slave Bluetooth device must include two ormore separate Bluetooth transceiver circuits to enable simultaneousactive connections to a corresponding two or more other master Bluetoothdevices.

Various embodiments of the present disclosure may arise from the presentrealization that a slave Bluetooth device can control a single Bluetoothtransceiver to sequentially establish connections to a plurality ofmaster Bluetooth devices, and then alternate between those connectionsto serve communications from the master Bluetooth devices at a rate thatis sufficient to prevent any of the master Bluetooth devices fromerroneously determining that the slave Bluetooth device is missing(e.g., beyond communication range or powered-off) and resultantlytearing down its respective connection to the slave Bluetooth device.The slave Bluetooth device requests that each of the master Bluetoothdevices use a timeout value(s) that is sufficiently large to allow theslave Bluetooth device to alternate between the simultaneously activeconnections to separately service communications with the masterBluetooth devices. The timeout value may be communicated by the slaveBluetooth device as a slave latency, connection interval, and/orconnection supervision timeout that the master Bluetooth devices arerequested to use to manage the connection to the slave Bluetooth device.A Connection Supervision Timeout value specifies the maximum time aconnection peer Bluetooth device not receiving any transfer, to considerthe connection lost.

These and other embodiments will be explained in further detail below inthe non-limiting context of an In-flight entertainment (IFE) system thatincludes seat video display units (SVDUs) which each have a singleBluetooth transceiver that is operated in a slave mode to connect toother Bluetooth devices operates in a master mode. The other Bluetoothdevices having Bluetooth transceivers can include, without limitation,wireless passenger control units (WPCUs), wireless mouse controllers(WMCs), passenger wireless headphones, passenger mobile phones, tabletcomputers, laptop computers, fitness trackers, heartrate monitors, otherpassenger wearables, etc. Each SVDU can be configured to be mechanicallyconnected to a seat frame within a vehicle, such as within a seat back,an arm rest, etc. The Bluetooth transceivers are configured to transmitand receive radio frequency (RF) signals in the ISM band. Althoughvarious embodiments herein are primarily described in the context of anIFE system deployed onboard an aircraft, the invention is not limitedthereto. Instead, these and other related embodiments may be used tocontrol Bluetooth transceivers located in any type of device and for anytype of system application. Various embodiments disclosed herein may beparticularly advantageous for deployment in systems that include apotentially large number of Bluetooth transceivers, where unnecessaryduplication of transceivers in each of the deployed devices can beprohibitively expensive and complex, such as in vehicles, includingwithout limitation, trains, automobiles, cruise ships, and buses, and inother non-vehicle installations, including without limitation, meetingrooms, sports stadiums, etc.

Embodiments are also described in the context of the Bluetoothtransceivers being configured to transmit and receive using radioresources in the ISM band. As used herein, the term “ISM band” refers toone or more frequency ranges that are reserved internationally for theuse of radio frequency energy for unlicensed and/or licensedcommunications. The term “band” can refer to one continuous frequencyrange or a plurality of non-continuous frequency ranges that are definedby the ITU Radio Regulations for ISM communications.

FIG. 1 illustrates an aircraft cabin 140 containing an IFE system thatprovides entertainment services to passengers. The IFE system caninclude a content server 160 that streams and/or downloads electroniccontent through wired networks (e.g., Ethernet) and/or through wirelessaccess points (WAPs) 150 to seat video display units (SVDUs) 110 thatmay be mounted to structures within the aircraft, including toseatbacks, seat armrests/frames, bulkheads, overhead structures, etc.The content server 160 may additionally stream and/or downloadelectronic content through WAPs 150 to passenger equipment carriedon-board by passengers, such as mobile phones, tablet computers, laptopcomputers, etc. The SVDUs 110 each contain a Bluetooth transceiver thatwirelessly communicates through ISM band RF signaling with Bluetoothtransceivers within various types of passenger controllers, which may bereleasable docked to an armrest docket station and/or a docket stationconnected to or adjacent to some/all of the SVDUs 110. The SVDUs 110 mayadditionally communicate with various types devices that a passenger canbring on board the aircraft, such as wireless headphones and mobilecomputing devices, such as cellular phones, tablet computers, laptopcomputers, etc. The Bluetooth transceiver within a SVDU 110 isunderstood to be the communication circuitry (i.e., transceiver, signalprocessor, etc.) which can be incorporated within the same housing thatat least partially encloses a display device, video display circuitry,network interface, and other circuitry providing functionality for theSVDU 110.

FIG. 2 is a block diagram illustrating some components of the IFE systemof FIG. 1 that are configured to operate in accordance with someembodiments of the present disclosure. Referring to FIG. 2, the IFEsystem includes system devices that can be located at each passengerseat location, and which are configured to communicate with varioustypes of passenger equipment that can be carried on-board by passengers.The seat-located system devices can communicate using RF resourceswithin the ISM band with the passenger equipment using an IEEE 802.11acwireless network 204 and/or a Bluetooth wireless networks 230 a,b. Theexample passenger equipment includes a passenger mobile terminal 200having a Bluetooth transceiver and wireless headphones 202.

The system devices can include a SVDU 110, a wireless passenger controlunit (WPCU) 206 and a wireless mouse controller (WMC) 204 that eachinclude a Bluetooth transceiver that establishes a connection to theSVDU 110. The WPCU 206 may be docked in a PCU docking station 218 forcharging and may be networked therethrough to the SVDU 110 via thebackbone network 2018. The WMC 204 may be a trackpad mounted in a seatarmrest or seat deployable food tray. The SVDUs 110 are connected torequest and receive content from a central content server through abackbone network 208, such as 1000 base-T Ethernet. The WPCU 206 and theWMC 204 can be operated by a passenger to wirelessly control the SVDU110, such as to select content that is consumed from the content server(e.g., played through a display device), select among displayed menuitems, and control other operations of the SVDU 110.

The example SVDU 110 includes a display device, video display circuitry,a general-purpose processor, a Bluetooth transceiver, and an Ethernetinterface or other wired network interface. The WPCU 206 and the WMC 204each can include a general-purpose processor and a Bluetoothtransceiver, and may include display circuitry connected to a displaydevice, and/or audio decoding circuitry connected to a wired headphonejack. The WPCU 206 may be a handheld device that is owned by theaircraft operator and provided for temporary use by a passenger during aflight.

FIG. 2 illustrates an example configuration of components for two spacedapart seat locations 220 a and 220 b. Each seat location 220 a/220 b isillustrated as being configured to include a passenger equipment 210that includes, but is not limited to, the passenger terminal 200 (e.g.,cellular phone, laptop computer, tablet computer, etc.) and the wirelessheadphones 202. These per-seat component configurations can bereplicated for any number of seat locations, such as being replicatedfor hundreds of seats to form an IFE system within an aircraft.

As will be explained in further detail below, each SVDU 110 establishesBluetooth connections with each of the various devices, e.g., WMC 204,the WPCU 206, the wireless headphones 202, and the passenger terminal200 to form a Bluetooth network 230 a/230 b.

FIGS. 3A-3B are a combined block diagram and data flow diagramillustrating operations and methods for establishing connections fromone SVDU device operating as a slave to a plurality of other devicesoperating as masters. The slave device then alternates between theconnections to service communications from the master devices.

In the illustrated example, the SVDU device 110 contains a Bluetoothtransceiver that is configured to operate in a slave mode whencommunicating through connections established to other devices. The WPCUdevice 206, the wireless headphones 202, and the passenger terminal 200each contain a Bluetooth transceiver that is configured to operate in amaster mode when communicating through their respective connectionsestablished to the SVDU device 110. The SVDU is therefore also referredto as a Bluetooth slave SVDU 110. Similarly, the WPCU device is alsoreferred to as a Bluetooth master WPCU 206, the wireless headphones isalso referred to as a Bluetooth master wireless headphones 202, and thepassenger terminal is also referred to as a Bluetooth master passengerterminal 200.

Referring to FIG. 3A, the Bluetooth slave SVDU 110 establishes (block300) a first connection through the Bluetooth transceiver with theBluetooth master WPCU device 206 that operates in a master mode. TheBluetooth slave SVDU 110 operates in a slave mode when communicatingthrough the first connection. The Bluetooth slave SVDU 110 generates andcommunicates (block 302) a first connection parameter update requestpacket containing a first timeout value through the Bluetoothtransceiver and the first connection to the Bluetooth master WPCU device206.

The Bluetooth slave SVDU 110 establishes (block 304) a second connectionthrough the Bluetooth transceiver with the Bluetooth master wirelessheadphones 202 that operates in a master mode. The Bluetooth slave SVDU110 operates in a slave mode when communicating through the secondconnection. The Bluetooth slave SVDU 110 generates and communicates(block 306) a second connection parameter update request packetcontaining a second timeout value through the Bluetooth transceiver andthe second connection to the Bluetooth master wireless headphones 202.

The Bluetooth slave SVDU 110 establishes (block 308) a third connectionthrough the Bluetooth transceiver with the Bluetooth master passengerterminal 200 that operates in a master mode. The Bluetooth slave SVDU110 operates in a slave mode when communicating through the thirdconnection. The Bluetooth slave SVDU 110 generates and communicates(block 310) a third connection parameter update request packetcontaining a third timeout value through the Bluetooth transceiver andthe third connection to the Bluetooth master passenger terminal 200.

Referring to FIG. 3B which illustrates operations occurring subsequentto block 310 of FIG. 3A, the Bluetooth slave SVDU 110 alternates duringnon-overlapping time slots between at least: 1) monitoring the firstconnection for traffic transmitted by the Bluetooth master WPCU device206 while not monitoring the second and third connections; 2) monitoringthe second connection for traffic transmitted by the Bluetooth masterwireless headphones 202 while not monitoring the first and thirdconnections; and 3) monitoring the third connection for traffictransmitted by the Bluetooth master passenger terminal 200 while notmonitoring the first and second connections. Although FIGS. 3A and 3Billustrate only three connections being established and serviced, theoperations disclosed herein may be used to establish and the service anyplural number of connections.

More specifically, the Bluetooth slave SVDU 110 during a first time slotperforms operations (block 312) to monitor, receive, and acknowledgetraffic that is transmitted by the Bluetooth master WPCU device 206through the first connection. During a subsequent second time slot,which does not overlap with the first time slot, the Bluetooth slaveSVDU 110 performs operations (block 314) to monitor, receive, andacknowledge traffic that is transmitted by the Bluetooth master wirelessheadphones 202 through the second connection. During a subsequent thirdtime slot, which does not overlap with the first and second time slots,the Bluetooth slave SVDU 110 performs operations (block 316) to monitor,receive, and acknowledge traffic that is transmitted by the Bluetoothmaster passenger terminal 200 through the third connection.

The Bluetooth slave SVDU 110 then repeats the alternating servicing ofthe first through third connections, by during a fourth time slot, whichdoes not overlap the first three third time slots, performing operations(block 318) to monitor, receive, and acknowledge traffic that istransmitted by the Bluetooth master WPCU device 206 through the firstconnection. During a subsequent fifth time slot, which does not overlapwith the first through fourth time slots, the Bluetooth slave SVDU 110performs operations (block 320) to monitor, receive, and acknowledgetraffic that is transmitted by the Bluetooth master wireless headphones202 through the second connection. During a subsequent sixth time slot,which does not overlap with the first through fifth time slots, theBluetooth slave SVDU 110 performs operations (block 322) to monitor,receive, and acknowledge traffic that is transmitted by the Bluetoothmaster passenger terminal 200 through the third connection.

In this manner, the Bluetooth slave SVDU 110 continues to repeat (block330) the above alternating rotation of sequentially monitoring,receiving, acknowledging traffic through the first, second, and thirdconnections. The traffic can include, but is not limited to, user data,Bluetooth commands for acknowledging receipt of data from another deviceand/or for signaling to maintain the connection (e.g., polling requestsand acknowledgement responses), instructions, etc. For example, whilethe Bluetooth slave SVDU 110 is monitoring the first, second, or thirdconnection for traffic transmitted by the respective master Bluetoothdevice, it communicates connection polling responses through themonitored connection responsive to corresponding connection pollingrequests that are received through that connection.

Although FIG. 3B illustrates a sequential alternating order of the firstconnection, then the second connection, and then the third connection,the Bluetooth slave SVDU 110 can choose any order of alternating betweenthe active connections. The order and frequency and which variousconnections are services may be determined by the Bluetooth slave SVDU110 based on priority of traffic carried by the connection, quality ofservice requirements of traffic carried by the connection, requirementsfor signaling a corresponding master that the connection as active, etc.The Bluetooth slave SVDU 110 may be controlled to return to a connectionmore frequently than one or more other connections based on one or moreof these considerations.

The Bluetooth slave SVDU 110 controls a rate at which the alternating,between servicing the first through third connections, is performedbased on the respective first, second, and third timeout values. Therate is controlled so that the Bluetooth slave SVDU 110 returns to eachof the respective first, second, and third connections with sufficienttimeliness so that the associated Bluetooth master device does noterroneously determine that the Bluetooth slave SVDU 110 is missing(e.g., beyond communication range or powered-off) and resultantlytearing down its respective connection to the Bluetooth slave SVDU 110.

In one embodiment, the Bluetooth transceiver of the Bluetooth slave SVDU110 is controlled to alternate between the connections, by operationsthat include: controlling the Bluetooth transceiver to cease monitoringthe first connection and to resume monitoring the second connection,based on expiration of a first time slot during the monitoring of thefirst connection, where the first time slot is defined based on thefirst timeout value; controlling the Bluetooth transceiver to ceasemonitoring the second connection and to resume monitoring the thirdconnection, based on expiration of a second time slot during themonitoring of the second connection, where the second time slot isdefined based on the second timeout value; and controlling the Bluetoothtransceiver to cease monitoring the third connection and to resumemonitoring the first connection, based on expiration of a third timeslot during the monitoring of the third connection, where the third timeslot is defined based on the third timeout value.

In one embodiment, the first, second, and third timeout values areequal, which may correspond to the Bluetooth slave SVDU 110 each of thefirst, second, and third connections for a same time duration beforealternating to monitor another one of the connections. In anotherembodiment, the Bluetooth slave SVDU 110 can be configured to monitorthe first, second, and third connections for a different time durationswhich may be determined based on characteristics of the traffic that isexpected to be sent through the respective connection, based on the timeduration that the associated master device will wait before erroneouslydetermining that the Bluetooth slave SVDU 110 is no longer accessible,and/or based on one or more other factors.

In another embodiment, the first timeout value is determined based on amaximum length of time that the Bluetooth slave SVDU 110 is allowed toremain not monitoring the first connection while it monitors the secondconnection or the third connection. The second timeout value issimilarly determined based on a maximum length of time that theBluetooth slave SVDU 110 is allowed to remain not monitoring the secondconnection while it monitors at least the first connection or the thirdconnection. The third timeout value is similarly determined based on amaximum length of time that the Bluetooth slave SVDU 110 is allowed toremain not monitoring the third connection while it monitors at leastthe first connection or the second connection.

In a further embodiment, the Bluetooth slave SVDU 110 determines thefirst timeout value based on a rate at which traffic is expected to betransmitted through the first connection by the Bluetooth master WPCUdevice 206, determines the second timeout value based on a rate at whichtraffic is expected to be transmitted through the second connection bythe Bluetooth master wireless headphones 202, and determines the thirdtimeout value based on a rate at which traffic is expected to betransmitted through the third connection by the Bluetooth masterpassenger terminal 200.

The first, second, and third timeout values may be determined based on acombination of the rates at which traffic is expected to be transmittedthrough the first, second, and third connections by the respectivemaster devices.

The master Bluetooth devices may operate to continuously carouseltime-stamped application data through their respective connections.During carouseling, the master repetitively retransmits its applicationdata with a fixed time-stamp. Carouseling time-stamped application dataenables the Bluetooth slave SVDU needing to signal for flow control. Inthis manner, the SVDU can leave (stop monitoring) a connection whilealternating through other connections to be monitored, and then returnto the connection to receive the application data which is identified asbeing new to the SVDU based on the fixed time-stamp received with theapplication data.

Referring to the embodiment illustrated in FIG. 4, the Bluetooth slaveSVDU 110 generates (block 400) the first timeout value as a first slavelatency value that defines a maximum number of polling requeststransmitted by the Bluetooth master WPCU device 206 through the firstconnection that the Bluetooth slave SVDU 110 can ignore without sendingan acknowledgement response to the Bluetooth master WPCU device 206before triggering the Bluetooth master WPCU device 206 to tear down thefirst connection. The first slave latency value is communicated (block410) to the Bluetooth master WPCU device 206 in a connection parameterupdate request packet.

The operations of blocks 400 and 410 can be repeated for the otherconnections. More particularly, the Bluetooth slave SVDU 110 cangenerate the second timeout value as a second slave latency value thatdefines a maximum number of polling requests transmitted by theBluetooth master wireless headphones 202 through the second connectionthat the Bluetooth slave SVDU 110 can ignore without sending anacknowledgement response to the Bluetooth master wireless headphones 202before triggering the Bluetooth master wireless headphones 202 to teardown the second connection. The Bluetooth slave SVDU 110 can generatethe third timeout value as a third slave latency value that defines amaximum number of polling requests transmitted by the Bluetooth masterpassenger terminal 200 through the third connection that the Bluetoothslave SVDU 110 can ignore without sending an acknowledgement response tothe Bluetooth master passenger terminal 200 before triggering theBluetooth master passenger terminal 200 to tear down the thirdconnection.

In another embodiment, the Bluetooth slave SVDU 110 generates the firstconnection parameter update request packet to contain the first timeoutvalue and to further contain a first connection interval value that isdetermined based on a maximum length of time that the Bluetooth slaveSVDU 110 is allowed to remain not monitoring the first connection whileit monitors the second or third connections. The second connectionparameter update request packet is generated to contain the secondtimeout value and to further contain a second connection interval valuethat is determined based on a maximum length of time that the Bluetoothslave SVDU 110 is allowed to remain not monitoring the second connectionwhile it monitors the first or third connections. The third connectionparameter update request packet is generated to contain the thirdtimeout value and to further contain a third connection interval valuethat is determined based on a maximum length of time that the Bluetoothslave SVDU 110 is allowed to remain not monitoring the third connectionwhile it monitors the first or second connections.

Referring to the embodiment illustrated in FIG. 5, the Bluetooth slaveSVDU 110 maintains (block 500) a first rotation timer that tracks howlong the Bluetooth slave SVDU 110 has not been continuously monitoringthe first connection while monitoring the second or third connections,and controls (block 510) timing for when the Bluetooth slave SVDU 110alternates back to monitoring the first connection responsive to thefirst rotation timer. The operations of blocks 505 10 can be similarlyrepeated to maintain rotation timers for each of the other connections.By way of example, the Bluetooth slave SVDU 110 can maintain a secondrotation timer that tracks how long the Bluetooth slave SVDU 110 has notbeen continuously monitoring the second connection while monitoring thefirst or third connections, and control timing for when the Bluetoothslave SVDU 110 alternates back to monitoring the second connectionresponsive to the second rotation timer. Further, the Bluetooth slaveSVDU 110 can maintain a third rotation timer that tracks how long theBluetooth slave SVDU 110 has not been continuously monitoring the thirdconnection while monitoring the first or second connections, and controltiming for when the Bluetooth slave SVDU 110 alternates back tomonitoring the third connection responsive to the third rotation timer.

A master Bluetooth transceiver (referred to as a “master” for brevity)schedules the transmission of a slave Bluetooth transceiver (eachreferred to as a “slave” for brevity) based on traffic demands to andthe slave and any other slaves that may be sharing the channel. Inaddition, the master supports regular transmissions to keep the slavesynchronized to the channel. The slave can listens in themaster-to-slave slots for packets. From the type indication in thepacket, the number of slots the master has reserved for its transmissioncan be derived; during this time, the slave does not have to listen onthe master-to-slave slots. A periodic master transmission is required tokeep the slave synchronized to the channel. Since the slave only needsthe channel access code to synchronize with, any packet type can be usedfor this purpose.

NULL packets can be sent by a master and used by the slave to maintainsynchronization. The POLL packet can be similar to the NULL packet andit does not have a payload. In contrast to the NULL packet, the POLLpacket requires a confirmation from the slave. Upon reception of a POLLpacket the slave should respond with a packet. This return packet is animplicit acknowledgement of the POLL packet. The POLL packet can be usedby the master in a piconet to poll the slave, which should then respondeven if they does not have information to send.

When a connection between a master and slave device is established(connected mode), the master decides how often to synchronize with theslave. The slave cannot force the master to use a particular value,however in accordance with various embodiments herein, the slave sends aconnection parameter update request packet that contains a timeout valuewhich is requested that the master use to set how long the slave can benonresponsive to POLL packets or other traffic from the master beforethe master tears down the connection to slave.

In some embodiments, the slave includes a connection interval and aslave latency in the connection parameter update request packet. Theslave latency value defines the number of times that the slave canignore a connection event transmitted by the master, before the masterdetermines that the slave is no longer connected to the master andresponsively tears down the connection to the slave. The slave latencyvalue is an integer specifying the number of connection events that maybe ignored. For example, the following code means that the slave canignore four consecutive connection events, but must then return to theparticular connection and service the fifth connection event:

-   -   #define SLAVE_LATENCY 4 // four connection events can be        ignored, the fifth must be responded to//

If there is no new data for the slave to transmit to the master, theslave can ignore the number of consecutive connection event specified bythe slave latency value. During this period of time that the slave isignoring connection events in a particular connection with one master,it alternates among other connections to service communications fromother masters before returning to the particular connection.

In a further embodiment, the slave defines the timeout valuecommunicated in the connection parameter update request packet, as aconnection supervision timeout value that defines the time that themaster will wait for a data transfer from the slave before assuming thatthe connection to the slave has been lost.

FIG. 6 illustrates Bluetooth discovery and connection operations with awhitelist and channel-map in accordance with some embodiments of thepresent disclosure. Referring to FIG. 6, a Bluetooth transceiver in, forexample, a passenger's wireless headphones, can transition from Standbystate to set discovery/connection policy 600, and set scan channels (CH)and connection-peer parameters 602. The Bluetooth transceiver set atimer 604, and performs inquiry operations 606 to find other Bluetoothtransceivers. For Bluetooth Classic (BLC), the inquiry can use 32inquiry channels to send INQUIRY messages to reach an INQUIRY_SCANdevice in 1 of the 32 inquiry channels. An inquiry scan 607 in BLC caninvolve hopping to a single frequency from the 16, to listen long enoughfor an inquiring device to cover 16 frequencies. The transceiverresponds to an INQUIRY message by sending an INQUIRY response. Theinquiry scan generates a list of General/Unlimited Inquiry Access Codes(GIACs) for discovered devices, which is filtered based on a whitelist608 with only the GIACs contained in the whitelist being allowed forconnection. The Bluetooth transceiver performs paging 610 to initiateconnection to a peer Bluetooth transceiver among the GIACs in thewhitelist 608.

In parallel operations, another Bluetooth transceiver in a SVDU cantransition from Standby state to set discovery/connection policy 620,and set scan channels (CH) and connection-peer parameters 622. TheBluetooth transceiver set a backoff timer 624, and performs inquiry scanoperations 626 to find other Bluetooth transceivers. The inquiry scangenerates a list of General/Unlimited Inquiry Access Codes (GIACs) fordiscovered devices, which is filtered based on a whitelist 628 with onlythe GIACs contained in the whitelist being allowed for connection. TheBluetooth transceiver sends an inquiry response 631 to the otherBluetooth transceiver that identifies the channel and an access code foruse in connecting to the Bluetooth transceiver.

The Bluetooth transceiver performs page scanning 632 to acceptconnection to the other (peer) Bluetooth transceiver, which is confirmedas being among the GIACs in the whitelist 634 and 612 by both Bluetoothtransceivers.

The Bluetooth transceiver in the headphones provides a masterpage-response 614, which is answered as a slave page-response 636 by theBluetooth transceiver in the SVDU. The Bluetooth transceiver in theheadphones then operates in a master connected mode for communicationswith the SVDU, while the Bluetooth transceiver in the SVDU operates in aslave connected mode for communications with the headphones.

In BLC, the connection process requires messaging between the master andslave that includes the following. Similar to INQUIRY messages sent on 2frequency trains of 16 frequencies, the initiator sends a PAGErequesting connection with target device . . . , upon target devicereceiving a PAGE-RESPONSE, it proceeds to next step. In the pageresponse, an acknowledgement is sent back to the MASTER containing theSLAVE ID. Upon the MASTER receiving response, it stops frequency hoppinggenerator & sends an FHS packet to the SLAVE. The hopping sequence isdetermined by the hop-set generator uses 28 bits of the MASTER's deviceaddress & 27 bits of MASTER's clock value (thus repetition interval ofthe sequence is 2^27, i.e. more than 23 Hrs). The newly generated hopsequence has low correlation with others & sweeps across all availablefrequencies with equal probability.

The SLAVE sends a response based on its native clock . . . , using thedata from the FHS packet, the SLAVE calculates adopts the MASTER'sfrequency hopping pattern & synchronizes to its clock. When the MASTERreceives the packet, it assigns the SLAVE an Active-Member-Address forthe piconet & hops to the new frequency. The MASTER sends a POLL tocheck whether the SLAVE is on the same frequency . . . , upon receivingthe POLL, to signal MASTER to be on the same channel, SLAVE sends apacket (usually a NULL packet) within a specified timeout period . . . ,the two devices have formed a MASTER/SLAVE relationship & are connected.By configuring POLL response time in to be long, the MASTER/SLAVE devicecan preserve connection for considerably LONG times.

In Bluetooth Low Energy (BLE), a connection is formed by advertisementand scan processes that include the following. A BLE advertisercontinuously sends advertising PDUs in advertising events composed ofone or more advertising PDUs, broadcasting on three advertisingchannels, i.e., channel 37, 38 & 39. There are two kinds of AdvertisingEvents in BLE Undirected Advertising & Directed Advertising events. TheUndirected Advertising Event contains ADV_IND, ADV_NONCONN_IND, orADV_SCAN_IND PDUs, which are used for detecting unknown device yetallows different responses. The time between the starts of twoconsecutive ADV-EVENT is the sum of ADV-INTERVAL & ADV-DELAY,ADV-INTERVAL is Rand[3, 16384]×625 uS, ranging from 20 mS to 10.24 S.ADV_DELAY is a random, RAND[0, 1024]×625 uS, ranging from 0-10 mSgenerated by Link Layer for each event.

Simultaneously, a BLE scanner/initiator scans these advertising channelsfor a SCAN-WINDOW time during SCAN-INTERVAL Upon receiving anADVERTISEMENT packet in a advertising channel, the scanner/initiatorwill send back a response. For example, a scanner sends SCAN_REQ to theadvertiser asking for more information, or an initiator sends CONN_REQto establish a connection—the response types are determined by thereceiver role & type of advertising event.

Disconnection of a connection is performed responsive to any of: 1)Connection-Establishment Failure—when connection request doesn't reachadvertiser or if advertiser rejects it; 2) voluntary termination, wherea peer may self-determine to terminate connection by sendingLL_TERMINATE_IND PDU; and 3) Connection Timeout—for when connected peerfails to ACK or send any data within connection timeout period.

FIG. 7 is a flowchart and data flow diagram for various operationalstates of Bluetooth transceivers in the Bluetooth devices (e.g., SVDU110, WPCU 206, headphones 202, terminal 200, etc.) of the system ofFIGS. 1-6 in accordance with some embodiments of the present disclosure.

Referring to FIG. 7, the type of operations performed by a Bluetoothtransceiver depends upon the state of the Bluetooth transceiver'sconnection, which include includes: unconnected/disconnected;connecting; and connected. In the unconnected/disconnected state, theBluetooth transceiver can operate in a statefull sleep operational mode,which is a lower power mode. In the connecting state, the Bluetoothtransceiver operates to perform connection establishment (paging),device discovery (inquiry), and/or re-connection responsive to a lostconnection. Connection establishment operations can include performingpaging and paging scan. Device discovery operations can includeperforming inquiry and inquiry scan.

In the connected state, the Bluetooth transceiver performs idleoperations (radio-on) while waiting for data to be received (via anantenna) into the receive FIFO buffer and waiting for data to be inputto the transmit FIFO buffer awaiting transmission through the antenna.The Bluetooth transceiver also performs hold mode operations, Park modeoperations, sniff mode operations, operations to receive data throughthe antenna into the receive FIFO buffer (e.g., for output to theprocessor of the Bluetooth device), and operations to transmit data thathas been input to the transmit FIFO buffer (e.g. by the processor of theBluetooth device) for transmission through the antenna.

FIG. 8 is a state diagram for various operational states of Bluetoothtransceivers devices (e.g., SVDU 110, WPCU 206, headphones 202, terminal200, etc.) of the system of FIGS. 1-7 in accordance with someembodiments of the present disclosure. Referring to FIG. 7, a Bluetoothtransceiver can perform operations corresponding to the standby state800, scanning state 802, initiator state 804, advertising state 806, andconnected state 808. A Bluetooth transceiver can lose its Bluetoothconnection to another device. FIG. 8 illustrates the state transitions830 of a Bluetooth transceiver operating as a master device and furtherillustrates the state transitions 810 of another Bluetooth transceiveroperating as a slave device, according to various embodiments herein.

Example Slave and Master Bluetooth Devices

FIG. 9 is a block diagram of a display unit, such as the SVDU 110, thatis configured to operate in accordance with some embodiments of thepresent disclosure. The display unit includes at least one processorcircuit 900 (referred to as a processor for brevity), at least onememory circuit 910 (referred to as a memory for brevity), a Bluetoothtransceiver 920, and a display device 940 (e.g., graphical displaydevice that may include a touch sensitive display). The display unit mayfurther include a user input interface 950 (e.g., keypad, buttons, touchsensitive interface, etc.) and/or an Ethernet or other wired networkinterface 930.

The processor 900 may include one or more data processing circuits, suchas a general purpose and/or special purpose processor (e.g.,microprocessor and/or digital signal processor) that may be collocatedor distributed across one or more networks. The processor 900 isconfigured to execute computer program code in the memory 910, describedbelow as a non-transitory computer readable medium, to perform at leastsome of the operations described herein as being performed by a displayunit, such as a SVDU, or by any other device that operates in aBluetooth slave mode. The computer program code when executed by theprocessor 900 causes the processor 900 to perform operations inaccordance with one or more embodiments disclosed herein for the displayunits disclosed herein. The processor 900 controls what content isplayed (e.g., television shows, movies), displayed (e.g., electronicbooks), executed (e.g., gaming programs), and/or otherwise consumedthrough the display unit responsive to commands received through theBluetooth transceiver 920 via connections that have been establishedwith various other devices operating in a Bluetooth master mode.

FIG. 10 is a block diagram of a Bluetooth device 1000, such as one ofthe various WPCU, WMC, mobile computing device (wireless headphones,passenger terminal, etc.) disclosed herein, configured to operate inaccordance with some embodiments of the present disclosure. TheBluetooth device 1000 includes at least one processor circuit 1000(referred to as a processor for brevity), at least one memory circuit1010 (referred to as a memory for brevity), and a Bluetooth transceiver1020. The Bluetooth device 1000 may further include a display device1030 (e.g., graphical display device that may include a touch sensitivedisplay), a user input interface 1040 (e.g., keypad, buttons, touchsensitive interface, etc.), and/or a cellular and/or Wi-Fi transceiver1050.

The processor 1000 may include one or more data processing circuits,such as a general purpose and/or special purpose processor (e.g.,microprocessor and/or digital signal processor) that may be collocatedor distributed across one or more networks. The processor 1000 isconfigured to execute computer program code in the memory 1010,described below as a non-transitory computer readable medium, to performat least some of the operations described herein as being performed by aBluetooth device that is operating in a master Bluetooth mode. Thecomputer program code when executed by the processor 1000 causes theprocessor 1000 to perform operations in accordance with one or moreembodiments disclosed herein for the display units disclosed herein.

Further Definitions and Embodiments

In the above-description of various embodiments of the presentdisclosure, aspects of the present disclosure may be illustrated anddescribed herein in any of a number of patentable classes or contextsincluding any new and useful process, machine, manufacture, orcomposition of matter, or any new and useful improvement thereof.Accordingly, aspects of the present disclosure may be implemented inentirely hardware, entirely software (including firmware, residentsoftware, micro-code, etc.) or combining software and hardwareimplementation that may all generally be referred to herein as a“circuit,” “module,” “component,” or “system.” Furthermore, aspects ofthe present disclosure may take the form of a computer program productcomprising one or more computer readable media having computer readableprogram code embodied thereon.

Any combination of one or more computer readable media may be used. Thecomputer readable media may be a computer readable signal medium or acomputer readable storage medium. A computer readable storage medium maybe, for example, but not limited to, an electronic, magnetic, optical,electromagnetic, or semiconductor system, apparatus, or device, or anysuitable combination of the foregoing. More specific examples (anon-exhaustive list) of the computer readable storage medium wouldinclude the following: a portable computer diskette, a hard disk, arandom access memory (RAM), a read-only memory (ROM), an erasableprogrammable read-only memory (EPROM or Flash memory), an appropriateoptical fiber with a repeater, a portable compact disc read-only memory(CD-ROM), an optical storage device, a magnetic storage device, or anysuitable combination of the foregoing. In the context of this document,a computer readable storage medium may be any tangible medium that cancontain, or store a program for use by or in connection with aninstruction execution system, apparatus, or device.

A computer readable signal medium may include a propagated data signalwith computer readable program code embodied therein, for example, inbaseband or as part of a carrier wave. Such a propagated signal may takeany of a variety of forms, including, but not limited to,electro-magnetic, optical, or any suitable combination thereof. Acomputer readable signal medium may be any computer readable medium thatis not a computer readable storage medium and that can communicate,propagate, or transport a program for use by or in connection with aninstruction execution system, apparatus, or device. Program codeembodied on a computer readable signal medium may be transmitted usingany appropriate medium, including but not limited to wireless, wireline,optical fiber cable, RF, etc., or any suitable combination of theforegoing.

Computer program code for carrying out operations for aspects of thepresent disclosure may be written in any combination of one or moreprogramming languages, including an object oriented programming languagesuch as Java, Scala, Smalltalk, Eiffel, JADE, Emerald, C++, C#, VB.NET,Python or the like, conventional procedural programming languages, suchas the “C” programming language, Visual Basic, Fortran 2003, Perl, COBOL2002, PHP, ABAP, dynamic programming languages such as Python, Ruby andGroovy, or other programming languages. The program code may executeentirely on the user's computer, partly on the user's computer, as astand-alone software package, partly on the user's computer and partlyon a remote computer or entirely on the remote computer or server. Inthe latter scenario, the remote computer may be connected to the user'scomputer through any type of network, including a local area network(LAN) or a wide area network (WAN), or the connection may be made to anexternal computer (for example, through the Internet using an InternetService Provider) or in a cloud computing environment or offered as aservice such as a Software as a Service (SaaS).

Aspects of the present disclosure are described herein with reference toflowchart illustrations and/or block diagrams of methods, apparatus(systems), and computer program products according to embodiments of thedisclosure. It will be understood that each block of the flowchartillustrations and/or block diagrams, and combinations of blocks in theflowchart illustrations and/or block diagrams, can be implemented bycomputer program instructions. These computer program instructions maybe provided to a processor of a general purpose computer, specialpurpose computer, or other programmable data processing apparatus toproduce a machine, such that the instructions, which execute via theprocessor of the computer or other programmable instruction executionapparatus, create a mechanism for implementing the functions/actsspecified in the flowchart and/or block diagram block or blocks.

These computer program instructions may also be stored in a computerreadable medium that when executed can direct a computer, otherprogrammable data processing apparatus, or other devices to function ina particular manner, such that the instructions when stored in thecomputer readable medium produce an article of manufacture includinginstructions which when executed, cause a computer to implement thefunction/act specified in the flowchart and/or block diagram block orblocks. The computer program instructions may also be loaded onto acomputer, other programmable instruction execution apparatus, or otherdevices to cause a series of operational steps to be performed on thecomputer, other programmable apparatuses or other devices to produce acomputer implemented process such that the instructions which execute onthe computer or other programmable apparatus provide processes forimplementing the functions/acts specified in the flowchart and/or blockdiagram block or blocks.

It is to be understood that the terminology used herein is for thepurpose of describing particular embodiments only and is not intended tobe limiting of the invention. Unless otherwise defined, all terms(including technical and scientific terms) used herein have the samemeaning as commonly understood by one of ordinary skill in the art towhich this disclosure belongs. It will be further understood that terms,such as those defined in commonly used dictionaries, should beinterpreted as having a meaning that is consistent with their meaning inthe context of this specification and the relevant art and will not beinterpreted in an idealized or overly formal sense unless expressly sodefined herein.

The flowchart and block diagrams in the figures illustrate thearchitecture, functionality, and operation of possible implementationsof systems, methods, and computer program products according to variousaspects of the present disclosure. In this regard, each block in theflowchart or block diagrams may represent a module, segment, or portionof code, which comprises one or more executable instructions forimplementing the specified logical function(s). It should also be notedthat, in some alternative implementations, the functions noted in theblock may occur out of the order noted in the figures. For example, twoblocks shown in succession may, in fact, be executed substantiallyconcurrently, or the blocks may sometimes be executed in the reverseorder, depending upon the functionality involved. It will also be notedthat each block of the block diagrams and/or flowchart illustration, andcombinations of blocks in the block diagrams and/or flowchartillustration, can be implemented by special purpose hardware-basedsystems that perform the specified functions or acts, or combinations ofspecial purpose hardware and computer instructions.

The terminology used herein is for the purpose of describing particularaspects only and is not intended to be limiting of the disclosure. Asused herein, the singular forms “a”, “an” and “the” are intended toinclude the plural forms as well, unless the context clearly indicatesotherwise. It will be further understood that the terms “comprises”and/or “comprising,” when used in this specification, specify thepresence of stated features, integers, steps, operations, elements,and/or components, but do not preclude the presence or addition of oneor more other features, integers, steps, operations, elements,components, and/or groups thereof. As used herein, the term “and/or”includes any and all combinations of one or more of the associatedlisted items. Like reference numbers signify like elements throughoutthe description of the figures.

The corresponding structures, materials, acts, and equivalents of anymeans or step plus function elements in the claims below are intended toinclude any disclosed structure, material, or act for performing thefunction in combination with other claimed elements as specificallyclaimed. The description of the present disclosure has been presentedfor purposes of illustration and description, but is not intended to beexhaustive or limited to the disclosure in the form disclosed. Manymodifications and variations will be apparent to those of ordinary skillin the art without departing from the scope and spirit of thedisclosure. The aspects of the disclosure herein were chosen anddescribed in order to best explain the principles of the disclosure andthe practical application, and to enable others of ordinary skill in theart to understand the disclosure with various modifications as aresuited to the particular use contemplated.

The invention claimed is:
 1. A slave Bluetooth device comprising: aBluetooth transceiver; at least one processor connected to the Bluetoothtransceiver; and at least one memory connected to the at least oneprocessor and storing program code that is executed by the at least oneprocessor to perform operations comprising: establishing a firstconnection through the Bluetooth transceiver with a first masterBluetooth device that operates in a master mode, wherein the slaveBluetooth device operates in a slave mode when communicating through thefirst connection; communicating a first connection parameter updaterequest packet containing a first timeout value through the Bluetoothtransceiver and the first connection to the first master Bluetoothdevice; and establishing a second connection through the Bluetoothtransceiver with a second master Bluetooth device that operates in amaster mode, wherein the slave Bluetooth device operates in the slavemode when communicating through the second connection; communicating asecond connection parameter update request packet containing a secondtimeout value through the Bluetooth transceiver and the secondconnection to the second master Bluetooth device; and alternating duringnon-overlapping time slots between at least: 1) monitoring the firstconnection for traffic transmitted by the first master Bluetooth devicewhile not monitoring the second connection; and 2) monitoring the secondconnection for traffic transmitted by the second master Bluetooth devicewhile not monitoring the first connection; and controlling a rate atwhich the alternating is performed based on the first timeout value andthe second timeout value.
 2. The slave Bluetooth device of claim 1,wherein controlling the rate at which the alternating is performed basedon the first timeout value and the second timeout value, comprises:controlling the Bluetooth transceiver to cease monitoring the firstconnection and to resume monitoring the second connection, based onexpiration of a first time slot during the monitoring of the firstconnection, the first time slot is defined based on the first timeoutvalue; and controlling the Bluetooth transceiver to cease monitoring thesecond connection and to resume monitoring the first connection, basedon expiration of a second time slot during the monitoring of the secondconnection, the second time slot is defined based on the second timeoutvalue.
 3. The slave Bluetooth device of claim 1, wherein: the firsttimeout value is the same as the second timeout value.
 4. The slaveBluetooth device of claim 1, wherein the operations further comprise:determining the first timeout value based on a maximum length of timethat the slave Bluetooth device is allowed to remain not monitoring thefirst connection while it monitors at least the second connection; anddetermining the second timeout value based on a maximum length of timethat the slave Bluetooth device is allowed to remain not monitoring thesecond connection while it monitors at least the first connection. 5.The slave Bluetooth device of claim 4, wherein the operations furthercomprise: sequentially and separately establishing a further connectionthrough the Bluetooth transceiver with each of a plurality of othermaster Bluetooth devices that each operates in a master mode, whereinthe slave Bluetooth device operates in the slave mode when communicatingthrough any of the further connections; responsive to each establishmentof one of the further connections with one of the other master Bluetoothdevices, performing operations to: determine a further timeout valuebased on a maximum length of time that the slave Bluetooth device isallowed to remain not monitoring the one of the further connections withthe one of the other master Bluetooth devices while it alternatesbetween monitoring other connections that have been established; andcommunicate a further connection parameter update request packetcontaining the further timeout value through the Bluetooth transceiverand the one of the further connections to the one of the other masterBluetooth devices; and the alternating during the non-overlapping timeslots is between each of the first, second, and the further connections.6. The slave Bluetooth device of claim 5, further comprising: a seatvideo display unit (SVDU), of a vehicle entertainment system, that haselectronically integrated therein the slave Bluetooth device and adisplay device that controls what content is displayed responsive to atleast some of the traffic that is received through each of the first,second, and the further connections, wherein the SVDU is configured tobe mechanically connected to a seat frame within a vehicle.
 7. The slaveBluetooth device of claim 6, wherein: the first connection isestablished with a wireless passenger control unit (WPCU) device havingan interface that is operable by a passenger supported by the seat frameconnected to the SVDU; the second connection is established with apassenger mobile computing device that is operable by the passengersupported by the seat frame connected to the SVDU; one of the furtherconnections is established with passenger wireless headphones; andanother one of the further connections is established with a wirelessmouse controller device having an interface that is operable by thepassenger supported by the seat frame connected to the SVDU.
 8. Theslave Bluetooth device of claim 1, wherein the operations furthercomprise: determining the first timeout value based on a rate at whichtraffic is expected to be transmitted through the first connection bythe first master Bluetooth device; and determining the second timeoutvalue based on a rate at which traffic is expected to be transmittedthrough the second connection by the second master Bluetooth device. 9.The slave Bluetooth device of claim 8, wherein the operations furthercomprise: further determining the first timeout value based on acombination of the rate at which traffic is expected to be transmittedthrough the first connection by the first master Bluetooth device andthe rate at which traffic is expected to be transmitted through thesecond connection by the second master Bluetooth device; and furtherdetermining the second timeout value based on a combination of the rateat which traffic is expected to be transmitted through the secondconnection by the second master Bluetooth device and the rate at whichtraffic is expected to be transmitted through the first connection bythe first master Bluetooth device.
 10. The slave Bluetooth device ofclaim 1, wherein the operations further comprise: generating the firsttimeout value as a first slave latency value that defines a maximumnumber of polling requests transmitted by the first master Bluetoothdevice through the first connection that the slave Bluetooth device canignore without sending an acknowledgement response to the first masterBluetooth device before triggering the first master Bluetooth device totear down the first connection; and generating the second timeout valueas a second slave latency value that defines a maximum number of pollingrequests transmitted by the second master Bluetooth device through thesecond connection that the slave Bluetooth device can ignore withoutsending an acknowledgement response to the second master Bluetoothdevice before triggering the second master Bluetooth device to tear downthe second connection.
 11. The slave Bluetooth device of claim 10,wherein: while monitoring the first connection for traffic transmittedby the first master Bluetooth device, communicating connection pollingresponses through the first connection responsive to correspondingconnection polling requests that are received through the firstconnection; and while monitoring the second connection for traffictransmitted by the second master Bluetooth device, communicatingconnection polling responses through the second connection responsive tocorresponding connection polling requests that are received through thesecond connection.
 12. The slave Bluetooth device of claim 1, whereinthe operations further comprise: generating the first connectionparameter update request packet to contain the first timeout value andto further contain a first connection interval value that is determinedbased on a maximum length of time that the slave Bluetooth device isallowed to remain not monitoring the first connection while it monitorsat least the second connection; and generating the second connectionparameter update request packet to contain the second timeout value andto further contain a second connection interval value that is determinedbased on a maximum length of time that the slave Bluetooth device isallowed to remain not monitoring the second connection while it monitorsat least the first connection.
 13. The slave Bluetooth device of claim1, wherein the operations further comprise: maintaining a first rotationtimer that tracks how long the slave Bluetooth device has not beencontinuously monitoring the first connection while monitoring the secondconnection any other connection with any one or more other masterBluetooth devices; controlling timing for when the slave Bluetoothdevice alternates back to monitoring the first connection responsive tothe first rotation timer; maintaining a second rotation timer thattracks how long the slave Bluetooth device has not been continuouslymonitoring the second connection while monitoring the first connectionany other connection with any one or more other master Bluetoothdevices; and controlling timing for when the slave Bluetooth devicealternates back to monitoring the second connection responsive to thesecond rotation timer.
 14. A video display unit of an entertainmentsystem comprising: a display device; a Bluetooth transceiver; at leastone processor connected to the Bluetooth transceiver and the displaydevice; and at least one memory connected to the at least one processorand storing program code that is executed by the at least one processorto perform operations comprising: establishing a first connectionthrough the Bluetooth transceiver with Bluetooth headphones that operatein a master mode, wherein the Bluetooth transceiver operates in a slavemode when communicating through the first connection; communicating afirst connection parameter update request packet containing a firsttimeout value through the Bluetooth transceiver and the first connectionto the Bluetooth headphones; and establishing a second connectionthrough the Bluetooth transceiver with a Bluetooth and cellular mobileterminal that operates in a master mode, wherein the Bluetoothtransceiver operates in the slave mode when communicating through thesecond connection; communicating a second connection parameter updaterequest packet containing a second timeout value through the Bluetoothtransceiver and the second connection to the Bluetooth and cellularmobile terminal; and alternating during non-overlapping time slotsbetween at least: 1) monitoring the first connection for traffictransmitted by the Bluetooth headphones while not monitoring the secondconnection; and 2) monitoring the second connection for traffictransmitted by the Bluetooth and cellular mobile terminal while notmonitoring the first connection; and controlling a rate at which thealternating is performed based on the first timeout value and the secondtimeout value.
 15. The video display unit of claim 14, furthercomprising: determining the first timeout value based on a maximumlength of time that the Bluetooth transceiver is allowed to remain notmonitoring the first connection while it monitors at least the secondconnection; and determining the second timeout value based on a maximumlength of time that the Bluetooth transceiver is allowed to remain notmonitoring the second connection while it monitors at least the firstconnection, wherein controlling the rate at which the alternating isperformed based on the first timeout value and the second timeout value,comprises: controlling the Bluetooth transceiver to cease monitoring thefirst connection and to resume monitoring the second connection, basedon expiration of a first time slot during the monitoring of the firstconnection, the first time slot is defined based on the first timeoutvalue; and controlling the Bluetooth transceiver to cease monitoring thesecond connection and to resume monitoring the first connection, basedon expiration of a second time slot during the monitoring of the secondconnection, the second time slot is defined based on the second timeoutvalue.
 16. The video display unit of claim 14, wherein the operationsfurther comprise: generating the first timeout value as a first slavelatency value that defines a maximum number of polling requeststransmitted by the Bluetooth headphones through the first connectionthat the Bluetooth transceiver can ignore without sending anacknowledgement response to the Bluetooth headphones before triggeringthe Bluetooth headphones to tear down the first connection; andgenerating the second timeout value as a second slave latency value thatdefines a maximum number of polling requests transmitted by theBluetooth and cellular mobile terminal through the second connectionthat the Bluetooth transceiver can ignore without sending anacknowledgement response to the Bluetooth and cellular mobile terminalbefore triggering the Bluetooth and cellular mobile terminal device totear down the second connection.
 17. The video display unit of claim 16,wherein: while monitoring the first connection for traffic transmittedby the Bluetooth headphones, communicating connection polling responsesthrough the first connection responsive to corresponding connectionpolling requests that are received through the first connection; andwhile monitoring the second connection for traffic transmitted by theBluetooth and cellular mobile terminal, communicating connection pollingresponses through the second connection responsive to correspondingconnection polling requests that are received through the secondconnection.
 18. A method of operating a slave Bluetooth device, themethod comprising: establishing a first connection through a Bluetoothtransceiver with a first master Bluetooth device that operates in amaster mode, wherein the slave Bluetooth device operates in a slave modewhen communicating through the first connection; communicating a firstconnection parameter update request packet containing a first timeoutvalue through the Bluetooth transceiver and the first connection to thefirst master Bluetooth device; and establishing a second connectionthrough the Bluetooth transceiver with a second master Bluetooth devicethat operates in a master mode, wherein the slave Bluetooth deviceoperates in the slave mode when communicating through the secondconnection; communicating a second connection parameter update requestpacket containing a second timeout value through the Bluetoothtransceiver and the second connection to the second master Bluetoothdevice; and alternating during non-overlapping time slots between atleast: 1) monitoring the first connection for traffic transmitted by thefirst master Bluetooth device while not monitoring the secondconnection; and 2) monitoring the second connection for traffictransmitted by the second master Bluetooth device while not monitoringthe first connection; and controlling a rate at which the alternating isperformed based on the first timeout value and the second timeout value.19. The method of claim 18, further comprising: determining the firsttimeout value based on a maximum length of time that the Bluetoothtransceiver is allowed to remain not monitoring the first connectionwhile it monitors at least the second connection; and determining thesecond timeout value based on a maximum length of time that theBluetooth transceiver is allowed to remain not monitoring the secondconnection while it monitors at least the first connection, whereincontrolling the rate at which the alternating is performed based on thefirst timeout value and the second timeout value, comprises: controllingthe Bluetooth transceiver to cease monitoring the first connection andto resume monitoring the second connection, based on expiration of afirst time slot during the monitoring of the first connection, the firsttime slot is defined based on the first timeout value; and controllingthe Bluetooth transceiver to cease monitoring the second connection andto resume monitoring the first connection, based on expiration of asecond time slot during the monitoring of the second connection, thesecond time slot is defined based on the second timeout value.
 20. Themethod of claim 18, wherein the operations further comprise: generatingthe first timeout value as a first slave latency value that defines amaximum number of polling requests transmitted by the Bluetoothheadphones through the first connection that the Bluetooth transceivercan ignore without sending an acknowledgement response to the Bluetoothheadphones before triggering the Bluetooth headphones to tear down thefirst connection; and generating the second timeout value as a secondslave latency value that defines a maximum number of polling requeststransmitted by the Bluetooth and cellular mobile terminal through thesecond connection that the Bluetooth transceiver can ignore withoutsending an acknowledgement response to the Bluetooth and cellular mobileterminal before triggering the Bluetooth and cellular mobile terminaldevice to tear down the second connection.